{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-05-26T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":45948,"title":"Function minimization - beat fminbnd!","description":"Matlab's fminbnd function finds a minimizer of a function within an interval. If often gets stuck in local minima.\r\n\r\nCan you do better than fminbnd, for a single variable?\r\n\r\nYou are given a function handler *fun* (one scalar input, one scalar output) and a the search bounds *xmin* and *xmax*. Return a minimizer *xopt* between *xmin* and *xmax* such that *fun(xopt) \u003c fminbnd(fun,xmin,xmax)*\r\n\r\nCheck Problem 45951 for the unbounded version (harder)!\r\n\r\n\u003chttps://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\u003e","description_html":"\u003cp\u003eMatlab's fminbnd function finds a minimizer of a function within an interval. If often gets stuck in local minima.\u003c/p\u003e\u003cp\u003eCan you do better than fminbnd, for a single variable?\u003c/p\u003e\u003cp\u003eYou are given a function handler \u003cb\u003efun\u003c/b\u003e (one scalar input, one scalar output) and a the search bounds \u003cb\u003exmin\u003c/b\u003e and \u003cb\u003exmax\u003c/b\u003e. Return a minimizer \u003cb\u003exopt\u003c/b\u003e between \u003cb\u003exmin\u003c/b\u003e and \u003cb\u003exmax\u003c/b\u003e such that \u003cb\u003efun(xopt) \u0026lt; fminbnd(fun,xmin,xmax)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eCheck Problem 45951 for the unbounded version (harder)!\u003c/p\u003e\u003cp\u003e\u003ca href = \"https://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\"\u003ehttps://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\u003c/a\u003e\u003c/p\u003e","function_template":"function xopt = better_than_fminbnd(fun,xmin,xmax)\r\n  xopt=fminbnd(fun,xmin,xmax);\r\n  % Now what?\r\n  \r\nend","test_suite":"%% Anti-hack\r\nfiletext = fileread('better_than_fminbnd.m');\r\nfiletext(find(filetext == '%', 1, 'last') : end) = [];\r\nassert(isempty(strfind(filetext, '\u0026gt;')),       'File handling is forbidden.');\r\nassert(isempty(strfind(filetext, 'eval')),       'Eval forbidden.');\r\nassert(isempty(strfind(filetext, 'regexp')),     'Regexp forbidden.');\r\nassert(isempty(strfind(filetext, '!')),          'Shell commands are forbidden.');\r\nassert(isempty(strfind(filetext, 'mlock')),      'mlock is forbidden.');\r\nassert(isempty(strfind(filetext, 'munlock')),    'munlock is forbidden.');\r\nassert(isempty(strfind(filetext, '@')),          'Anonymous functions are forbidden.');\r\n\r\n%%\r\nfun=@(x)cos(x)-cos(pi*x)/pi;\r\nxmin=0;\r\nxmax=10*pi;\r\nxopt = better_than_fminbnd(fun,xmin,xmax);\r\nxsubopt = fminbnd(fun,xmin,xmax);\r\nyopt=fun(xopt)\r\nysubopt=fun(xsubopt)\r\nassert(xopt\u003e=xmin \u0026 xopt\u003c=xmax \u0026 fun(xopt) \u003c fun(xsubopt))\r\n\r\n%%\r\nfun=@(x)sin(20./x).*sin(20*x)\r\nxmin=1;\r\nxmax=5;\r\nxopt = better_than_fminbnd(fun,xmin,xmax);\r\nxsubopt = fminbnd(fun,xmin,xmax);\r\nyopt=fun(xopt)\r\nysubopt=fun(xsubopt)\r\nassert(xopt\u003e=xmin \u0026 xopt\u003c=xmax \u0026 fun(xopt) \u003c fun(xsubopt))","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":452188,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":8,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-06-15T17:34:38.000Z","updated_at":"2026-05-30T15:08:30.000Z","published_at":"2020-06-15T18:46:12.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMatlab's fminbnd function finds a minimizer of a function within an interval. If often gets stuck in local minima.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eCan you do better than fminbnd, for a single variable?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou are given a function handler\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003efun\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e (one scalar input, one scalar output) and a the search bounds\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmin\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmax\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e. Return a minimizer\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exopt\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e between\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmin\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmax\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e such that\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003efun(xopt) \u0026lt; fminbnd(fun,xmin,xmax)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eCheck Problem 45951 for the unbounded version (harder)!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:hyperlink w:docLocation=\\\"https://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"problems":[{"id":45948,"title":"Function minimization - beat fminbnd!","description":"Matlab's fminbnd function finds a minimizer of a function within an interval. If often gets stuck in local minima.\r\n\r\nCan you do better than fminbnd, for a single variable?\r\n\r\nYou are given a function handler *fun* (one scalar input, one scalar output) and a the search bounds *xmin* and *xmax*. Return a minimizer *xopt* between *xmin* and *xmax* such that *fun(xopt) \u003c fminbnd(fun,xmin,xmax)*\r\n\r\nCheck Problem 45951 for the unbounded version (harder)!\r\n\r\n\u003chttps://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\u003e","description_html":"\u003cp\u003eMatlab's fminbnd function finds a minimizer of a function within an interval. If often gets stuck in local minima.\u003c/p\u003e\u003cp\u003eCan you do better than fminbnd, for a single variable?\u003c/p\u003e\u003cp\u003eYou are given a function handler \u003cb\u003efun\u003c/b\u003e (one scalar input, one scalar output) and a the search bounds \u003cb\u003exmin\u003c/b\u003e and \u003cb\u003exmax\u003c/b\u003e. Return a minimizer \u003cb\u003exopt\u003c/b\u003e between \u003cb\u003exmin\u003c/b\u003e and \u003cb\u003exmax\u003c/b\u003e such that \u003cb\u003efun(xopt) \u0026lt; fminbnd(fun,xmin,xmax)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eCheck Problem 45951 for the unbounded version (harder)!\u003c/p\u003e\u003cp\u003e\u003ca href = \"https://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\"\u003ehttps://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\u003c/a\u003e\u003c/p\u003e","function_template":"function xopt = better_than_fminbnd(fun,xmin,xmax)\r\n  xopt=fminbnd(fun,xmin,xmax);\r\n  % Now what?\r\n  \r\nend","test_suite":"%% Anti-hack\r\nfiletext = fileread('better_than_fminbnd.m');\r\nfiletext(find(filetext == '%', 1, 'last') : end) = [];\r\nassert(isempty(strfind(filetext, '\u0026gt;')),       'File handling is forbidden.');\r\nassert(isempty(strfind(filetext, 'eval')),       'Eval forbidden.');\r\nassert(isempty(strfind(filetext, 'regexp')),     'Regexp forbidden.');\r\nassert(isempty(strfind(filetext, '!')),          'Shell commands are forbidden.');\r\nassert(isempty(strfind(filetext, 'mlock')),      'mlock is forbidden.');\r\nassert(isempty(strfind(filetext, 'munlock')),    'munlock is forbidden.');\r\nassert(isempty(strfind(filetext, '@')),          'Anonymous functions are forbidden.');\r\n\r\n%%\r\nfun=@(x)cos(x)-cos(pi*x)/pi;\r\nxmin=0;\r\nxmax=10*pi;\r\nxopt = better_than_fminbnd(fun,xmin,xmax);\r\nxsubopt = fminbnd(fun,xmin,xmax);\r\nyopt=fun(xopt)\r\nysubopt=fun(xsubopt)\r\nassert(xopt\u003e=xmin \u0026 xopt\u003c=xmax \u0026 fun(xopt) \u003c fun(xsubopt))\r\n\r\n%%\r\nfun=@(x)sin(20./x).*sin(20*x)\r\nxmin=1;\r\nxmax=5;\r\nxopt = better_than_fminbnd(fun,xmin,xmax);\r\nxsubopt = fminbnd(fun,xmin,xmax);\r\nyopt=fun(xopt)\r\nysubopt=fun(xsubopt)\r\nassert(xopt\u003e=xmin \u0026 xopt\u003c=xmax \u0026 fun(xopt) \u003c fun(xsubopt))","published":true,"deleted":false,"likes_count":1,"comments_count":0,"created_by":452188,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":8,"test_suite_updated_at":null,"rescore_all_solutions":false,"group_id":1,"created_at":"2020-06-15T17:34:38.000Z","updated_at":"2026-05-30T15:08:30.000Z","published_at":"2020-06-15T18:46:12.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eMatlab's fminbnd function finds a minimizer of a function within an interval. If often gets stuck in local minima.\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eCan you do better than fminbnd, for a single variable?\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYou are given a function handler\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003efun\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e (one scalar input, one scalar output) and a the search bounds\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmin\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmax\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e. Return a minimizer\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exopt\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e between\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmin\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e and\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003exmax\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e such that\u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:t\u003e \u003c/w:t\u003e\u003c/w:r\u003e\u003cw:r\u003e\u003cw:rPr\u003e\u003cw:b/\u003e\u003c/w:rPr\u003e\u003cw:t\u003efun(xopt) \u0026lt; fminbnd(fun,xmin,xmax)\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eCheck Problem 45951 for the unbounded version (harder)!\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:hyperlink w:docLocation=\\\"https://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\\\"\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026lt;https://www.mathworks.com/matlabcentral/cody/problems/45951-function-minimization-beat-fminsearch\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:hyperlink\u003e\u003cw:r\u003e\u003cw:t\u003e\u0026gt;\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"errors":[],"facets":[[],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"fminbnd\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}